Dr. Pedro Pérez-Segura

Dr. Pedro Pérez-Segura is one of Spain's most respected medical oncologists, leading the Gastrointestinal Oncology Unit at Hospital Clínico San Carlos in Madrid—one of Spain's largest and most historically significant university hospitals, affiliated with the Complutense University of Madrid. With over 25 years dedicated to oncology, he has developed a practice that sits at the intersection of clinical care, translational research, and hereditary cancer medicine, giving his patients access to both the most current treatments and to clinical trials of emerging therapies.

His central clinical focus is gastrointestinal malignancies: colorectal cancer, pancreatic cancer, and gastric cancer, which together account for a significant share of cancer deaths in Spain and across Europe. Within this field, Dr. Pérez-Segura has become particularly expert in precision oncology—the use of molecular tumor profiling to match patients with targeted therapies or immunotherapy based on the specific genetic alterations driving their tumor. He was an early adopter of routine BRAF and KRAS/NRAS mutation testing in colorectal cancer and has been involved in disseminating best-practice guidelines for molecular testing in Spain.

A distinctive element of his work is his specialization in hereditary colorectal cancer syndromes, particularly Lynch syndrome—an inherited condition caused by mismatch repair gene mutations that dramatically elevates the risk of colorectal, endometrial, and other cancers. Dr. Pérez-Segura leads a multidisciplinary hereditary cancer program that includes genetic counseling, family cascade testing, and risk-reduction surveillance strategies, working alongside geneticists and gastroenterologists to protect at-risk family members.

Patients from Spain and neighboring European countries consult Dr. Pérez-Segura for second opinions, complex case management, and access to clinical trials not available at smaller centers.

Dr. Pérez-Segura completed his medical degree at the Complutense University of Madrid, one of Spain's leading medical schools. He undertook his internal medicine internship and medical oncology residency at Hospital Clínico San Carlos, gaining broad oncological experience across tumor types. His PhD research, conducted within the oncology department and in collaboration with the Spanish National Cancer Research Centre (CNIO), focused on molecular markers of prognosis and treatment response in colorectal cancer—work that established his scientific credentials in translational oncology. He has completed additional training in hereditary cancer genetics and participates in international fellowships and observership programs in precision oncology in collaboration with European and North American cancer centers. He has served as associate professor of oncology at the Complutense University of Madrid, teaching medical students and oncology residents.

Dr. Pérez-Segura's clinical practice is built around the precision management of gastrointestinal tumors. For colorectal cancer, his standard of care includes reflex molecular testing for KRAS, NRAS, BRAF V600E, and microsatellite instability (MSI) status, which guides decisions on anti-EGFR therapy eligibility (cetuximab, panitumumab), BRAF-targeted combinations, and checkpoint inhibitor immunotherapy for MSI-High tumors. He is experienced in all-line therapy for metastatic colorectal cancer, including sequencing of FOLFOX, FOLFIRI, and FOLFOXIRI-based regimens with and without bevacizumab, as well as newer agents such as regorafenib and TAS-102.

For pancreatic cancer, he manages borderline resectable and metastatic disease with FOLFIRINOX or gemcitabine-nab-paclitaxel regimens, and assesses patients for germline BRCA testing that may enable PARP inhibitor maintenance therapy. His hereditary cancer clinic evaluates families with Lynch syndrome, familial adenomatous polyposis (FAP), and other hereditary colorectal cancer syndromes, coordinating surveillance colonoscopy, prophylactic surgery discussions, and genetic counseling. He actively enrolls eligible patients into phase I–III clinical trials available at his institution.

Dr. Pérez-Segura has published over 150 peer-reviewed papers, book chapters, and review articles in the field of gastrointestinal oncology and hereditary cancer. His research on BRAF and KRAS testing in colorectal cancer contributed to Spanish national guidelines and to ESMO and SEOM consensus recommendations for molecular testing in mCRC. His work on MSI-High tumors and their exceptional response to checkpoint inhibitor immunotherapy has helped establish pembrolizumab and nivolumab as standard-of-care options in Spain for eligible patients. He has contributed to European and Spanish hereditary CRC registries that track the clinical outcomes of Lynch syndrome families over time, providing some of the longest-term data available on penetrance and risk-reduction interventions. He serves on the scientific committee of SEOM and as a reviewer for major oncology journals, and has presented his research at ESMO, ASCO, and ECCB congresses.

Dr. Pérez-Segura receives international patients at Hospital Clínico San Carlos in central Madrid, a hospital with established pathways for foreign patients including administrative support, translation services, and coordination with international health insurers. Consultations are conducted in Spanish and English. EU patients seeking care in Spain can utilize the European Health Insurance Card (EHIC) for emergency treatment or apply for planned treatment reimbursement under EU Directive 2011/24/EU; non-EU patients are seen on a private basis with cost transparency provided in advance. Video consultations are available for initial case review and second-opinion discussions, which is particularly valuable for patients with newly diagnosed colorectal or pancreatic cancer seeking expert guidance on treatment sequencing, molecular testing interpretation, or clinical trial eligibility before deciding on a care pathway.

Dr. Pérez-Segura has received the SEOM Lifetime Achievement Award, the highest distinction bestowed by the Spanish Society of Medical Oncology, in recognition of his sustained contributions to gastrointestinal oncology research and clinical practice over more than two decades. He has received the Spanish National Cancer Research Centre (CNIO) Collaboration Award for his contributions to translational research bridging laboratory findings and clinical application in colorectal cancer. The European Society for Medical Oncology designated him an ESMO Fellow (FESMO), recognizing his international scientific standing. He has chaired or co-chaired scientific sessions at ESMO GI and SEOM congresses, served on SEOM guideline committees, and contributed to ESMO clinical practice guidelines for colorectal and pancreatic cancer.